Patient interface device for ophthalmic surgical laser system

ABSTRACT

Apparatus and method for interfacing an ophthalmic surgical laser system with a patient&#39;s eye using a single-piece patient interface (PI). The PI includes a hollow shell, with an applanation lens and a flexible skirt at its lower end. Through channels are formed around the applanation lens to connect the spaces above and below the lens. When the PI is coupled to the laser system and the eye, the upper rim of the shell forms a seal with the laser system and the flexible skirt forms a seal with the eye. A vacuum is applied to the interior of the shell via a vacuum port on the laser system, and the vacuum is communicated to the space enclosed by the applanation lens, the skirt and the eye through the channels around the lens. A magnetic mechanism is also provided to hold the PI shell to the laser system.

RELATED APPLICATIONS

This application claims priority to, and the benefit of, under U.S.C. §119(e) of U.S. Provisional Application No. 62/414,605, filed on Oct. 28,2016, which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION Field of the Invention

Embodiments of this invention generally relate to ophthalmic surgicallaser systems, and particularly to a patient interface device used tostabilize the patient's eye and to deliver the laser beam to the eyeduring ophthalmic surgery, as well as related methods.

Description of Related Art

Significant developments in laser technology have led to its applicationin the field of ophthalmic surgery, and laser surgery has become thetechnique of choice for ophthalmic surgical applications. Ophthalmicsurgery is a precision operation and requires precise coupling betweenthe surgical tool (i.e., the laser beam) and the region to be surgicallyaltered (i.e., a portion of the patient's eye). Movement of the eye withrespect to the intended focal point of the laser beam can lead tonon-optimal results and could even result in permanent damage to tissuewithin the eye. Given that eye movement is often the result of autonomicreflex, techniques have been developed in an attempt to stabilize theposition of a patient's eye with respect to an incident laser beam.

Mechanical stabilization devices, referred to as patient interfaces(PI), have been developed for coupling the patient's eye to the lasersystem. A PI has a component that directly contacts the eye, and engagesand stabilizes the eye; meanwhile, the PI is attached to the lasersystem, so that the laser beam can be aligned to the eye. Some PIs aredescribed in commonly-owned U.S. Pat. Appl. No. 2014/0276673. FIGS. 1-3Bof this application shows a PI which includes an ocular attachment ringthat couples to the eye, a gripper device, and a lens cone with anapplanation lens which is used to establish an appropriate optical pathalignment between the cornea and a laser optical path. The lens cone andthe ocular attachment ring are interfaced together by the gripperdevice. The ocular attachment ring has a skirt that forms an annularchannel between the eye and the skirt, and a vacuum can be applied tothe annular channel via tubing that connect the ocular attachment ringto a vacuum source. FIGS. 4-5A of the above application show another PIwith a fluid-filled bladder which can be placed on the patient's eye.FIGS. 6-10 of the above application show yet another PI where a fluidfills a space between the PI and the eye surface.

U.S. Pat. Appl. No. 2016/0151203 describes various PI designs, includinga one-piece configuration, a two-part configuration, and a liquidinterface two-part configuration. U.S. Pat. No. 9,089,401 describes a PIwhich includes, among other things, a connector that couples the PI tothe laser optical system and is configured to accommodate adjustment ofthe contact element of the PI, where the connector may include aflexible element, an elastic element, a magnetic coupling element, avacuum-suction element, a gravitational connector, a frictionalconnector or a viscous connector.

Many existing PIs use vacuum force to couple to the eye and stabilizethe eye during the surgical procedure. Many existing PIs attach to thelaser system via mechanical means, such as twist-to-lock, one-way slide,etc. A PI may be formed of a single component, or multiple componentsthat are joined together during the docking process (i.e., the procedureof engaging the eye with the laser system using the PI). With those PIsthat are comprised of multiple pieces, it can be difficult to join thepieces together especially if one portion is already in contact with thepatient and the other connected to the laser system.

SUMMARY

Embodiments of the present invention are directed to a patient interfacedevice and related method that substantially obviate one or more of theproblems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a patient interfacethat has a simple construction and is easy and convenient to use.

Additional features and advantages of the invention will be set forth inthe descriptions that follow and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims thereof as well as the appended drawings.

To achieve these and/or other objects, as embodied and broadlydescribed, an embodiment of present invention provides a patientinterface device for coupling an eye of a patient to an ophthalmicsurgical laser system, which includes: a hollow shell formed of a rigidmaterial and defining an interior space, the shell having an upper rimand a lower portion; a transparent applanation lens disposed inside ofand fixedly mounted to the lower portion of the hollow shell; and aflexible skirt having a circular shape, the flexible skirt being affixedto and extending downwardly from a lower end of the lower portion of theshell, wherein a lower rim of the flexible skirt is located below theapplanation lens, wherein the lower portion of the shell defines one ormore through channels in a region between the applanation lens and aside wall of the lower portion, to provide air communication between theinterior space of the shell above the applanation lens and a space whichis located below the applanation lens and encircled by the flexibleskirt.

In another aspect, an embodiment of present invention provides a systemfor delivering a laser beam from an ophthalmic surgical laser system toa patient's eye, which includes: a patient interface device, including:a hollow shell formed of a rigid material and defining an interiorspace, the shell having an upper rim and a lower portion; a transparentapplanation lens disposed inside of and fixedly mounted to the lowerportion of the hollow shell; and a flexible skirt having a circularshape, the flexible skirt being affixed to and extending downwardly froma lower end of the lower portion of the shell, wherein a lower rim ofthe flexible skirt is located below the applanation lens, wherein thelower portion of the shell defines one or more through channels in aregion between the applanation lens and a side wall of the lowerportion, to provide air communication between the interior space of theshell above the applanation lens and a space which is located below theapplanation lens and encircled by the flexible skirt; a laser deliverysystem coupled to the ophthalmic surgical laser system, including: adownwardly facing surface; and a patient interface mounting blockprotruding downwardly from the downwardly facing surface, the patientinterface mounting block including a lower portion having an opticalwindow near its bottom for delivering a laser beam generated by theophthalmic surgical laser system, the patient interface mounting blockdefining an air channel inside the block, a first end of the air channelbeing open on an exterior of the block, and a second end of the airchannel being configured to be connected to a vacuum source; and amagnetic mechanism for coupling the patient interface device to thelaser delivery system, comprising a first part and a second part, one ofthe first and second parts being a magnet and another one of the firstand second parts being either a magnet or a material attracted tomagnets, wherein the first part is incorporated in the patient interfacedevice and the second part is incorporated in the laser delivery system,wherein the first and second parts are located adjacent to each otherwhen the patient interface device is coupled to the laser deliverysystem, wherein when the patient interface device is coupled to thelaser delivery system, the patient interface mounting block isaccommodated inside the shell of the patient interface device with anair gap defined between the shell and the patient interface mountingblock, the air gap extending continuously between the first end of theair channel of the patient interface mounting block and the one or morethrough channels of the lower portion of the shell of the patientinterface, and the upper rim of the patient interface is in contact withthe downwardly facing surface of the laser delivery system to form aseal.

In another aspect, an embodiment of present invention provides a methodfor the system of claim 9 to couple the ophthalmic surgical laser systemto the patient's eye, which includes: manually placing the patientinterface device on the eye, wherein the flexible skirt of the patientinterface device contacts the eye; while manually holding the patientinterface device, moving the laser delivery system to a position abovethe patient interface device and aligned with the patient interfacedevice; lowering the laser delivery system until the upper rim of thepatient interface device is in contact with the downwardly facingsurface of the laser delivery system, whereby the magnetic mechanismgenerates a magnetic force to hold the patient interface device on thelaser delivery system; and applying a vacuum to the air channel of thepatient interface mounting block, whereby a vacuum is generated in theair gap between the shell and the patient interface mounting block tohold the patient interface device to the laser delivery system, andwhereby the vacuum is communicated to a space enclosed by theapplanation lens, the flexible skirt and the eye to hold the eye to thepatient interface device.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a bottom perspective view of a patient interface (PI) deviceaccording to an embodiment of the present invention.

FIG. 2 is a bottom perspective view showing the PI coupled to a laserdelivery system according to an embodiment of the present invention.

FIG. 3 is a bottom perspective view of the laser delivery system.

FIG. 4 is a side elevation view showing the PI coupled to the eye.

FIG. 5 is a sectional view of the PI coupled to the eye.

FIG. 6 is a sectional view of the PI and the laser delivery systemcoupled to each other.

FIG. 7 schematically illustrates a method for coupling the patient's eyewith the laser delivery system using the PI according to an embodimentof the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Embodiments of the invention provide an apparatus and related method forinterfacing an ophthalmic surgical laser system with a patient's eyeusing a single-piece patient interface (PI). The PI includes a hollowshell, with an applanation lens and a flexible skirt located at thebottom of a cone shaped portion of the shell. Through channels areformed between the applanation lens and the side wall of the cone shapedportion to connect the spaces above and below the applanation lens. Whenthe PI is coupled to the laser delivery system and the eye, the upperrim of the shell forms a seal with a downwardly facing surface of thelaser delivery system, and the flexible skirt forms a seal with the eye.A vacuum is applied to the interior of the shell via a vacuum port whichis located in the laser delivery system and opens to the interior of theshell, and the vacuum is communicated through the through channelsaround the applanation lens to the space below the applanation lens,i.e. the space enclosed by the applanation lens, the skirt and the eye.The vacuum securely holds the PI to both the laser delivery system andthe eye. A magnetic mechanism is also provided to hold the PI shell tothe laser delivery system to aid the eye docking process.

A PI and a laser delivery system according to embodiments of the presentinvention are described in more detail with reference to FIGS. 1-6.

As shown in FIG. 1 (bottom perspective view), the PI 100 is a singlepiece component, which is to be coupled at its upper side to the lowerend of a laser delivery system of a laser system, and coupled at itslower side to the patient's eye E via a flexible sealing skirt. FIG. 2(bottom perspective view) shows the PI 100 coupled to the laser deliverysystem 200. FIG. 3 (bottom perspective view) shows the laser deliverysystem 200 without the PI. FIG. 4 is a side elevation view showing thePI 100 coupled to the patient's eye E. FIG. 5 is a sectional view of thePI 100 coupled to the eye E, and FIG. 6 is a sectional view of the PI100 and the laser delivery system 200 coupled to each other. Thesections in FIGS. 5 and 6 are cut in a vertical direction indicated byarrows A-A′ of FIG. 4 along a center plane of the PI.

As shown in FIGS. 1-6, the PI 100 has a hollow shell 101 which includesan upper portion 102 and a lower portion 103. The upper portion 102 mayhave any suitable shape; in the illustrated embodiment, the upperportion 102 has the shape of an elongated tub with a flat bottom. Thelower portion 103 preferably has the shape of an upside-down truncatedcone, but it may also have a cylindrical shape, or other suitableshapes. In the illustrated embodiment, the lower portion 103 is locatedat one end of the elongated upper portion 102, but other configurationsmay also be used. For convenience, in this disclosure, the lower portion103 of the PI shell 101 is referred to as the cone portion and the upperportion 102 is referred to as the tub portion.

The lower end of the cone portion 103 includes a circular shapedflexible skirt 104. A transparent member 105, referred to as anapplanation lens, is disposed inside and fixedly mounted to the coneportion 103 of the shell. The applanation lens 105 may have a planar(horizontally oriented) or curved bottom surface, which is located abovethe lower rim of the flexible skirt 104. When the PI 100 is coupled tothe patient's eye E, the applanation lens 105 contacts and applanatesthe cornea of the eye, and the flexible skirt 104 contacts the eye'ssurface (e.g. the sclera) to create a seal between the PI and the eye.

In a ring shaped region between the applanation lens 105 and the sidewall of the cone portion 103, one or more through channels 106 areformed to connect the interior space of the hollow PI shell 101 abovethe applanation lens with a space 108C which is located below theapplanation lens 105 and encircled by the flexible skirt 104, i.e. aspace enclosed by the applanation lens, the flexible skirt and thesurface of the eye E when the PI 100 is coupled to the eye, to allowfluid (including air) communication between the two spaces.

The lower end of the laser delivery system 200 has a PI mounting block201 that protrudes downwardly from a generally flat and horizontallyoriented lower surface 207. The PI mounting block 201 has a size andshape that can be accommodated inside the hollow interior of the PIshell 101 when the PI 100 is coupled to the laser delivery system 200.The PI mounting block 201 includes a laser delivery portion 203 havingan upside-down truncated-cone shape or a cylindrical shape, or othersuitable shape, with an optical window 205 at its bottom from which thelaser beam of the laser system exits. The optical window 205 may be thesurface of an optical element such as a lens, a prism, etc., of thelaser delivery system 200. When the PI 100 is coupled to the laserdelivery system 200, the optical window 205 is located directly abovethe applanation lens 105 of the PI 100 for delivering the laser beaminto the eye.

When the PI 100 is coupled to the laser delivery system, the upper rim107 of the tub portion 102 of the PI shell 101 is in contact with thelower surface 207 of the laser delivery system 200 to create an airtight seal. The upper rim (upper seal) 107 of the PI shell 101 mayinclude a flexible material, and/or have a flange shape, to facilitatethe sealing with the laser delivery system 200.

In one embodiment, an upper portion 202 of the PI mounting block 201 anda part of the tub portion 102 of the PI shell 101 have a mating shape ina horizontal cross-section so that when the PI 100 is couple to thelaser delivery system 200 with the PI mounting block 201 containedinside the shell, the PI 100 is prevented from moving horizontallyrelative to the laser delivery system 200. This facilitates thealignment of the laser beam from the optical window 205 relative to theapplanation lens 105 and thus the alignment of the laser beam relativeto the eye. In an alternative embodiment, a groove is provided on thelower surface 207 of the laser delivery system 200, the groove having ashape that mates with the upper seal 107 of the PI 100, so that when thePI is coupled to the laser delivery system, the upper seal falls in thegroove and the PI is prevented from moving horizontally.

The size and shape of the hollow PI shell 101 and of the PI mountingblock 201 are such that a continuous air gap 108 is present betweenthem. A part of the air gap 108A extends between the laser deliveryportion 203 of the PI mounting block 201 and the cone portion 103 of thePI shell 101, so that the one or more through channels 106 locatedaround the applanation lens 105 are open to the air gap. For example,the air gap 108A may extend between the side walls of the laser deliveryportion 203 and the cone portion 103, and/or between the optical window205 of the laser delivery portion 203 and the applanation lens 105.

An air channel 206 is provided inside the PI mounting block 201 and isopen to the air gap 108 between the PI mounting block and the PI shell101. The other end of the air channel 206 is coupled via a pipe or othermeans to a vacuum source or suction pump, so that the air channel canfunctions as a vacuum port to create a vacuum in the air gap. In theillustrated embodiment, the opening 206A of the vacuum port 206 islocated on the bottom of the upper portion 202 of the PI mounting block201, and a part of the air gap 108 extends between the bottom surface ofthe upper portion 202 of the PI mounting block 201 and the flat bottompanel of the tub portion 102 of the PI shell 101.

A magnetic mechanism is provided to generate a magnetic attraction forcebetween the laser delivery system 200 and the PI 100. The magneticmechanism includes two parts, one being a magnet, the other being apiece of material that is attracted to magnets (e.g. a ferromagnetic orparamagnetic material such as steel and some other metals) or anothermagnet. The two parts are located respectively on the PI 100 and thelaser delivery system 200 at respective locations that are adjacent toeach other when the PI 100 is coupled to the laser delivery system 200.In one embodiment, as shown in FIGS. 5 and 6, a disk 109 made of amaterial that is attracted to magnets is affixed on the inside of thebottom panel of the tub portion 102, and the PI mounting block 201includes a magnet located at or near the bottom of the upper portion 202at a location adjacent to the disk 109 when the PI 100 is coupled to thelaser delivery system 200. Alternatively, the disk 109 is a magnet, anda magnet or a material that is attracted to magnets is provided at thecorresponding location of the upper portion 202 of the PI mounting block201. The disk 109 may be embedded or adhered to the bottom panel of thetub portion 102, or it may be an integral part of the PI shell 101 (forexample, the tub portion 102 or the bottom panel may be made of steel).In these embodiments, the two parts of the magnetic mechanism may be indirect contact with each other or have a small air gap between them whenthe PI 100 is coupled to the laser delivery system 200. Other spatialarrangements for the two parts may be employed, so long as they generatean adequate magnetic attraction force between the laser delivery system200 and the PI 100.

In preferred embodiments, the PI shell 101 is formed of a rigid materialsuch as rigid plastic, metal, etc., and the skirt 104 and the upper seal107 are formed of flexible materials, preferably a compliant natural orsynthetic polymer, such as silicone, flexible plastic, rubber, etc. Theflexible skirt 104 and the upper seal 107 are affixed to the PI shell101 in an air-tight manner by any suitable means such as adhesion, etc.The cone portion 103 and the tub portion 102 of the PI shell 101 arepreferably formed integrally, e.g., by molding, overmolding,thermoforming, etc. It should be noted that the design where the coneportion 103 of the PI shell 101 protrudes from the bottom of the tubportion 102 provides a clearance for the patient's face (e.g. bridge ofthe nose) to prevent possible interference when the PI is coupled to theeye. As stated earlier, the upper portion 102 of the PI shell may haveother suitable shapes, so long as it can accommodate the PI mountingblock and has an upper rim that can be sealed to a downwardly facingsurface of the laser delivery system 200.

In operation, the coupling of the PI 100 to the laser delivery system200 is accomplished by both the magnetic force generated by the magneticmechanism and a vacuum sealing force generated by a vacuum in the airgap 108. The coupling of the PI 100 to the patient's eye E isaccomplished by a vacuum sealing force generated by a vacuum in thespace 108C enclosed by the skirt 104, the applanation lens 105 and thesurface of the eye E. Because the space 108C is in fluid communicationwith the air gap 108, the same vacuum source generates the vacuumsealing force that seals the PI 100 to both the laser delivery system200 and the eye E.

The eye docking process during surgery, i.e., the process of engagingthe eye with the laser delivery system 200 using the PI 100, isdescribed with reference to FIG. 7.

First, the surgeon places the PI 100 on the patient's eye (which facesupward) such that the flexible skirt 104 contacts the eye (e.g. thesclera) (step S701). The cornea of the eye may be applanated by theapplanation lens 105 in this step. While manually holding the PI 100,the surgeon then brings the laser delivery system 200 to a position thatis above the PI and approximately aligned with the PI (step S701). Forexample, the optical window 205 of the laser delivery system 200 isapproximately aligned with the applanation lens 105, and the upperportion 202 of the PI mounting block 201 is approximately aligned withthe tub portion 102 of the PI shell 101. The surgeon then lowers thelaser delivery system 200, so that the PI mounting block 201 is loweredinto the hollow space of the PI shell 101, until the upper seal 107 ofthe PI 100 is in contact with the lower surface 207 of the laserdelivery system (step S703). At this time, the magnetic force generatedby the magnetic mechanism operates to hold the PI 100 on the laserdelivery system 200. During step S703, the magnetic mechanism allows thePI 100 to “snap” into place on the laser delivery system 200, andprovides a well-defined tactile feel of proper attachment of the PI 100to the system 200. Then, a vacuum is applied to the interior air gap 108between the PI shell 101 and the PI mounting block 201 via the vacuumport 206 (step S704). The vacuum pressure securely couples the PI 100 tothe laser delivery system 200. At the same time, through the one or morethrough channels 106 located around the applanation lens 105, the vacuumpressure is also applied to the space 108C enclosed by the applanationlens 105, the flexible skirt 104 and the surface of the eye E. Thisvacuum pressure securely couples the PI 100 to the eye. This completesthe docking process. The vacuum is continuously applied throughout thelaser surgery.

It is noted that the magnetic force generated by the magnetic mechanismonly needs to temporarily hold the PI 100 to the laser delivery system200 during docking. Therefore, only a moderate magnetic force isrequired, making it easy to remove the PI 100 from the laser deliverysystem 200 after the surgery. An optional handle 110 may be provided onthe PI 100 for convenient handling of the PI.

No other coupling mechanisms beside the magnetic mechanism and thevacuum seal between the upper seal 107 and the lower surface 207 of thelaser delivery system 200 are required to couple the PI 100 to the laserdelivery system. No twisting or lateral sliding actions are required tocouple the PI to the laser delivery system.

To summarize, the patient interface (PI) according to embodiments of thepresent invention is a single piece component that attaches to the laserdelivery system first via a magnetic mechanism that allows it to “snap”into place, and then by a vacuum sealing force.

The PI simplifies the docking process and reduces the time required forthe laser system attachment and readiness. The magnetic mechanism alsoprovides a well-defined tactile feel of proper attachment of the PI tothe system. The integrated vacuum port requires no tubing attachment tothe PI itself, which simplifies attachment and removal of the PI to andfrom the laser system, and also prevents vacuum tubing from interferingwith the surgeon's work area. The elimination of vacuum tubing andassociated fittings also reduces manufacturing cost of the PI.

The PI according to embodiments of the present invention can be used invarious ophthalmic laser systems, including, without limitation,femtosecond lasers for flap cutters and laser cataract systems.

It will be apparent to those skilled in the art that variousmodification and variations can be made in the patient interface deviceand the laser delivery system as well as related methods of the presentinvention without departing from the spirit or scope of the invention.Thus, it is intended that the present invention cover modifications andvariations that come within the scope of the appended claims and theirequivalents.

What is claimed is:
 1. A patient interface device for coupling an eye ofa patient to an ophthalmic surgical laser system, comprising: a hollowshell formed of a rigid material and defining an interior space, theshell having an upper rim and a lower portion; a transparent applanationlens disposed inside of and fixedly mounted to the lower portion of thehollow shell; and a flexible skirt having a circular shape, the flexibleskirt being affixed to and extending downwardly from a lower end of thelower portion of the shell, wherein a lower rim of the flexible skirt islocated below the applanation lens, wherein the lower portion of theshell defines one or more through channels in a region between theapplanation lens and a side wall of the lower portion, to provide aircommunication between the interior space of the shell above theapplanation lens and a space which is located below the applanation lensand encircled by the flexible skirt.
 2. The patient interface device ofclaim 1, wherein the upper rim of the shell includes a flexiblematerial.
 3. The patient interface device of claim 2, the flexiblematerial of the upper rim is a compliant natural or synthetic polymer.4. The patient interface device of claim 1, wherein the flexible skirtis made of a compliant natural or synthetic polymer.
 5. The patientinterface device of claim 1, wherein the lower portion of the shell hasa shape of an upside-down truncated cone.
 6. The patient interfacedevice of claim 5, wherein the shell further includes an upper portion,wherein an upper rim of the upper portion is the upper rim of the shell,and wherein the lower portion of the shell extends downwardly from theupper portion.
 7. The patient interface device of claim 6, furthercomprising a magnet or a piece of material that is attracted to magnets,affixed to the upper portion of the shell.
 8. The patient interfacedevice of claim 1, wherein the shell includes a magnet or a piece ofmaterial that is attracted to magnets.
 9. A system for delivering alaser beam from an ophthalmic surgical laser system to a patient's eye,comprising: a patient interface device, comprising: a hollow shellformed of a rigid material and defining an interior space, the shellhaving an upper rim and a lower portion; a transparent applanation lensdisposed inside of and fixedly mounted to the lower portion of thehollow shell; and a flexible skirt having a circular shape, the flexibleskirt being affixed to and extending downwardly from a lower end of thelower portion of the shell, wherein a lower rim of the flexible skirt islocated below the applanation lens, wherein the lower portion of theshell defines one or more through channels in a region between theapplanation lens and a side wall of the lower portion, to provide aircommunication between the interior space of the shell above theapplanation lens and a space which is located below the applanation lensand encircled by the flexible skirt; a laser delivery system coupled tothe ophthalmic surgical laser system, comprising: a downwardly facingsurface; and a patient interface mounting block protruding downwardlyfrom the downwardly facing surface, the patient interface mounting blockincluding a lower portion having an optical window near its bottom fordelivering a laser beam generated by the ophthalmic surgical lasersystem, the patient interface mounting block defining an air channelinside the block, a first end of the air channel being open on anexterior of the block, and a second end of the air channel beingconfigured to be connected to a vacuum source; and a magnetic mechanismfor coupling the patient interface device to the laser delivery system,comprising a first part and a second part, one of the first and secondparts being a magnet and another one of the first and second parts beingeither a magnet or a material attracted to magnets, wherein the firstpart is incorporated in the patient interface device and the second partis incorporated in the laser delivery system, wherein the first andsecond parts are located adjacent to each other when the patientinterface device is coupled to the laser delivery system, wherein whenthe patient interface device is coupled to the laser delivery system,the patient interface mounting block is accommodated inside the shell ofthe patient interface device with an air gap defined between the shelland the patient interface mounting block, the air gap extendingcontinuously between the first end of the air channel of the patientinterface mounting block and the one or more through channels of thelower portion of the shell of the patient interface, and the upper rimof the patient interface is in contact with the downwardly facingsurface of the laser delivery system to form a seal.
 10. The system ofclaim 9, wherein the upper rim of the shell includes a flexiblematerial.
 11. The system of claim 10, wherein the flexible material ofthe upper rim is a compliant natural or synthetic polymer.
 12. Thesystem of claim 9, wherein the flexible skirt is made of a compliantnatural or synthetic polymer.
 13. The system of claim 9, wherein thelower portion of the shell has a shape of an upside-down truncated cone.14. The system of claim 13, wherein the shell further includes an upperportion, wherein an upper rim of the upper portion is the upper rim ofthe shell, and wherein the lower portion of the shell extends downwardlyfrom the upper portion.
 15. The system of claim 14, wherein the firstpart of the magnetic mechanism is affixed to the upper portion of theshell.
 16. A method for the system of claim 9 to couple the ophthalmicsurgical laser system to the patient's eye, comprising: manually placingthe patient interface device on the eye, wherein the flexible skirt ofthe patient interface device contacts the eye; while manually holdingthe patient interface device, moving the laser delivery system to aposition above the patient interface device and aligned with the patientinterface device; lowering the laser delivery system until the upper rimof the patient interface device is in contact with the downwardly facingsurface of the laser delivery system, whereby the magnetic mechanismgenerates a magnetic force to hold the patient interface device on thelaser delivery system; and applying a vacuum to the air channel of thepatient interface mounting block, whereby a vacuum is generated in theair gap between the shell and the patient interface mounting block tohold the patient interface device to the laser delivery system, andwhereby the vacuum is communicated to a space enclosed by theapplanation lens, the flexible skirt and the eye to hold the eye to thepatient interface device.